Tailoring BiVO4 for Efficient Photocatalytic Water Splitting: Insights into Characteristics, Mechanism, and Future Prospects

The rising global demand for clean energy has accelerated interest in photoelectrochemical (PEC) water splitting as a sustainable route for solar hydrogen production. This paper reviews the role of BiVO 4 as a photoanode material for photoelectrochemical water splitting, its inherent limitations, and the effect of various synthesis techniques including sol–gel, hydrothermal, chemical precipitation, electrospray, and spin coating on its crystallinity, phase purity, morphology, and photoelectrochemical properties. The shortcomings of pure BiVO 4 , such as low charge carrier mobility, short hole diffusion length, and slow kinetics of surface oxidation, are tackled by the modification strategies such as (i) elemental doping with n -type and p -type dopants, (ii) heterojunction formation using TiO 2 , WO 3 , Fe 2 O 3 , and SrTiO 3, (iii) cocatalyst incorporation (NiFe-LDH, Co-Pi, MoS 2 ), and (iv) transport layer engineering. Significant improvements in transforming BiVO 4 from a photoanode to a photocathode by doping with an acceptor and regulating the phase of BiVO 4 are emphasized as an important development for obtaining all-BiVO 4 tandem devices. Apart from generating hydrogen gas, promising applications of BiVO 4 in environmental cleanup include photodegradation of organic pollutants, heavy metal removal, antibacterial efficacy, and sensor technology.